Conventionally, image processing may be performed by binarizing an image and regarding the parts with high brightness and low brightness as a half tone area and a character area, respectively. In the case that a dark colored or blackish photograph with rather low brightness is processed, the half-tone area and characters area are processed by the same technique using this method. Consequently, image after the processing lacks a stereoscopic effect and has a flat impression.
In some editorial works, it is necessary to combine sentences and pictures by cutting and pasting.
In order to fit a portion of a paper in a vacant area of another paper, the vacant area be exactly extracted because it must be clear before the insertion whether the area to be inserted fits the area as it is; if not, it must be contracted and the contraction scale must be determined. Automatic extraction of the vacant area is necessary to automatically insert an image into a vacant area of another image. However, a method for automatically extracting a vacant area does not heretofore exist, so far as the present inventors know.